用户指南和参考

样本程序段

考虑如何在 SQL 中创建和使用索引的如下示例。 有关 CREATE INDEX 和 CREATE INDEX EXTENSION 命令的更多信息,可参考 SQL Reference。 注意:在创建索引之后,就可发出使用 Spatial 函数和谓词的标准 DDL 和 DML 语句。

create table customers (cid int, addr varchar(40), ..., loc db2gse.ST_Point)
create table stores (sid int, addr varchar(40), ..., loc db2gse.ST_Point,
 zone db2gse.ST_Polygon)
 
create index customersx1 on customers(loc) extend using spatial_index(10e0, 100e0,
 1000e0)
create index storesx1 on stores(loc) extend using spatial_index(10e0, 100e0,
 1000e0)
create index storesx2 on stores(zone) extend using spatial_index(10e0, 100e0,
 1000e0)
 
insert into customers (cid, addr, loc) values (:cid, :addr, sdeFromBinary(:loc))
insert into customers (cid, addr, loc) values (:cid, :addr, geocode(:addr))
insert into stores (sid, addr, loc) values (:sid, :addr, sdeFromBinary(:loc))
 
update stores set zone = db2gse.ST_Buffer (loc, 2)
 
select cid, loc from customers
 where db2gse.ST_Within(loc, :polygon) = 1
 
select cid, loc from customers
 where db2gse.ST_Within(loc, :circle1) = 1 OR
       db2gse.ST_Within(loc, :circle2) = 1
 
select c.cid, loc from customers c, stores s
 where db2gse.ST_Contains(s.zone, c.loc) = 1 selectivity 0.01
 
select avg(c.income) from customers c
 where not exist (select * from stores s
                  where db2gse.ST_Distance(c.loc, s.loc) < 10)
 


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